Modeling, Monitoring and Control of Hydrocephalus. Our long range goal is to design and test a feedback control system for a better treatment of communicating hydrocephalus. New shunting systems equipped with a micro-electro telemetry volume sensor and monitor in conjunction with active feedback could significantly improve patient care and outcome if stage-specific intervention proves to be of importance in pathogenesis. Advances in MR phase contrast imaging and in-vivo intracranial pressure measurements provide new insights into the velocity and pressure distributions of cerebrospinal fluid in normal and hydrocephalic patients. A first principle model derived from our preliminary clinical and experimental work quantifies the CSF flow and the compliant brain tissue. Motivated by new data and modeling progress, it is proposed to explore the feasibility of a new micro-electro telemetry volume sensor for monitoring and directly controlling the ventricular size. For the exploratory R-21 program three specific goals are: Aim 1: Implementation of a fluid-structure interaction model for three-dimensional biomechanical deformation of the brain parenchyma in communicating hydrocephalus and validation of the model using MR imaging of hydrocephalic patients. Aim 2: The design of a micro-electro telemetry ventricular volume sensor and monitor Aim 3: A theoretical and experimental study of a feedback control shunt therapy with miniaturized volume sensor coupled with active micro pumping The novel sensor combined with active feedback control of ventricular size and ICP is expected to provide new diagnostic and therapeutic methods currently not available for patients suffering from communicating hydrocephalus. [unreadable] [unreadable] [unreadable]